Presently, various kinds of optical recording media including CD-R/RW, DVD-R/RW, MO and others have been widely accepted and used as external memory devices for information processing machines such as computers because a large quantity of information may be stored and randomly accessed easily as in DVD-RAM. Among the optical recording media, recordable optical recording media such as CD-R and DVD-R, which are organic dye type optical recording media having a recording layer containing organic dye compounds, have been considered to have advantages from the viewpoint of low cost and easy production.
Generally, the optical recording media such as CD-R and DVD-R that are available in the market are designed as, for example, in the case of CD-R, being suitable for recording and reading information with a laser light of about 780 nm wavelength, or in the case of DVD-R, being suitable for recording and reading information with a laser light of 600 nm to 700 nm wavelength. As a dye used for recording in CD-R or DVD-R, for example, an azo compound is used (refer to Patent Document 1, Patent Document 2, and Patent Document 3).
Patent Document 1: International Publication No. WO 91/018950,
Patent Document 2: Japanese Patent Application Laid-Open Publication No. H09-277703, and
Patent Document 3: Japanese Patent Application Laid-Open Publication No. 2001-271001.